SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b518f9f1db83a76a4281f0c99df976a5c1b386d6dcd1c4bc927087675f929203' 
  AND token = 'KaGHGn52w4jOssWYem/JNboNHwtzLgsb8K2fu5G4yk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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