SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afadc7133a19b523584d409eab3e1508c0e08511c5ff9ae186e527b7b90b56dc' 
  AND token = 'FQaopOA7VUBlkB1F8AEnUIJZror+G46AT/QgwTxgoyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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