SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd2584ba411599365c168a4e39084618d659c0e644072c3c87008e9a88bb1ff1' 
  AND token = 'UJO/wOpnwcNTZJeyjvtvkckito3TwZRFE8lciYsdUSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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