SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c5c39e430f15e3058bc78f11de9845a5655fb7b43c0fdb8885932c5c848492' 
  AND token = 'ik11b2FhmvrWdQvkVuBjZLp1EI2BgGaLtt/+q7alxJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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