SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9afa4039684e516997d06e59c584139c24937536898290521736079f9be1a817' 
  AND token = 'l9sVgWwBpVNBx/TjQF6Y9hujYAp/0YF21BLbA+mdv+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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