SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acf1fba54b1583736f056b045696058e3434e2f8b1880b962ffc7c40eeae1e3d' 
  AND token = 'YnaWUbaDNp8cTLsAZw62RR60BmbA0Bt2qG8cCs2PDig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}