SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5a7d1a28ec83b414fd6e201b787faf43f028b20c4e80cae81e57c26fedec430' 
  AND token = 'TwRIe8W5SphG3pjhUDNqtdrTZPJiXzpJeGnxMGhU3Cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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