SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd49864ba7ca1dc1acaa6c2b695ee9a914159084e7f1226cf4973ead976bb4e11' 
  AND token = 'hv4AlKEG4NJB7tIYhVJOaqVryqkr+UajSzaimZeLMCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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