SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccfc9dc80969888db20cbce2671f0de2cac4282a6b79db95d329585dc287dc09' 
  AND token = 'k6rUxbeDY2Rm99EDkRWf0V8D9jwOh6iJfHVwkFWytgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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