SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '996df458ad60f5f09fe46d13220a28751ead93fac7b08d0ad5f37d1538cec8e6' 
  AND token = 'H9hEaDqhu4cdwUJnlWZRuX+c1+Dbqx7dTER0EEymHiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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