SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64b24665a07d7a3e5316be173111fcfbd59d88b64afe0de5058cfbae54bc1af6' 
  AND token = 'MRwT4K9zbFVjIooNXjljWeg+OwiF9ldg+A805osWNzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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