SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49d3920e6bbc204617693fd4645b6dd868e57964ae43c7666af37a0689a7bca9' 
  AND token = 'TYJRW8IB3WtMwr/OqKmZsUfpSq1DBGKDeO+KWn2Wcog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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