SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99b277f94faab4a998995b1c02b1c75303405280c034e5e736ed7feffb385dc8' 
  AND token = 'LB7/fBSJ0Dp9abuSz+06fwHURYZI8vWZjLal8dAPyGo=' 
  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"
    }
  }
}