SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a0b3fed89bba353621e7a4aed4ed713495136a65019efd4ba811ccd67707a89' 
  AND token = 'gKyFEYb5aT4yRJa0Jry5ZY9ZjEyU67cuAcjiZyPXBLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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