SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1450e769ebff9d65cb2d0410f11213036252ad0944965c2ed5742913be88179' 
  AND token = 'V8e5RpmMcMcdBaHEhkErhlxU1/Oj4oslYwSIAwEsLIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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