SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99c7079fa2cb89863e795863fe871196f0203a2d73d21462919837c735436d28' 
  AND token = 'l77riBe0ZX0eNtZNvKMlIE12NNVuuK9WT091KUX7fME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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