SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6649f2e1822151a850d1dcee668ccbacefba28d48582a3b318a068e6703ef13' 
  AND token = 'VhhEaOmwdIR95gKL71B8KDRr++dLxISZvIJqyw1jsFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00101

JSON explain

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