SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4367db59d69c4417b69e3a3de59133652cd47495e08d580ee21d4827375d131' 
  AND token = '7sBOXQLDYH3x/X2vXNN4ufW+neQleOgkoSMZ6BDaeus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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