SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2898cca4a9bdb8c33a6790e085716ae6062c5ffb540be5a0e63e6433a7a4523' 
  AND token = 'Y7/TXKLeFpgRGySZYDfoJXmYv7sgbhRez66/pcjCRfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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