SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9a452af78c06ebe3774eb40b327318e07de41ace5fd99dbfcaee71f8e119d0b' 
  AND token = 'vtm44eSLzjn+jlYrTJNzBLFIv5QRUrxkjE9fq42DibE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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