SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4333ac9f6f7a3ffb1a8ec06c04392e48ca3948d783e9817fc2d44268cb4dbeda' 
  AND token = 'Phj0JavcjbRRReYcyuRXrSdJoyjBvZVtLJ3ifqH6P4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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