SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7aafd7ec8db167621a3ed08b886c406e815af73f712ba1d00b5773bf102d343' 
  AND token = 'sP8Z5LVZKb1TZp5UFCjctbMlcF+T79lJN6YmbBXEkNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}