SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1029fd5eb36de4e192051efbda320ad0c0e55c98628f0aced670e8a63c749b39' 
  AND token = 'wjLLklyeADetEjt1TQNAAPPPIzHy2wRexA2S/Yj9wMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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