SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '324749de4cfa5630253817afd51ad0fb3e8de55d0ffc9809abd3b352ccfa5b87' 
  AND token = '8KEHKEtNqNOzn7xGY8rEuU8dhQ52LDTLhj6/sAViBos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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