SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '570afafc8a4671cf44e52b246d716db81123a9aebfaf4e269ac5edb2b4fdf5e9' 
  AND token = 'No/lwYcCGQ78Zh88nmKkm5YQsIsBk2Qg83CYNBNvKUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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