SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '331e52641f3adb117ea5dc33f47f2416d2c84e3e50590a9dcb13980498e681d6' 
  AND token = '5eSiyM4sI6lOOKUKJnaj894RCjoZrc/s7F0Qq/EHnRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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