SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a7e3cebfd21c77236c0a0c43084efed74a88bca3535c9a7ec314eb3aeaae993' 
  AND token = 'jmV2hUzBuxrhCaY/84TDTjrV/pnwgTOhpgtf+hQVZYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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