SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd14141a5c2a349239214777879f523b65bee124fd118ef8ff4d86f1837be2eaf' 
  AND token = 'qA7ewjzzuoneevGReKkuPa5Ms44xM0Ojs6POXwPMl8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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