SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afaca75c8807ffa76164b34c8d867a1725a5642480b0f1895246f22d4585c070' 
  AND token = 'OUUf9j5e+qz2Vy+mBGRgPMurK6j96omubjpOjGGzH74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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