SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5903255f805c75b6f20cc5d5c293c5d48b7b7ea87edc5b873407cd026786b891' 
  AND token = 'bPLVepdaRlzAawNnlGmBFdGRJyaouBQxCiqWf57TqSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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