SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec43e302459f8d6393bc80d9eda81d849416a0e1c283eeaf715065d619cacdcf' 
  AND token = 'xBXITn0PLPOokhMhsEDBMPNTWm+eNctA0PkCK5det10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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