SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7859ff1ee963570946fb553b3b92fd925ee70574bf27ab605213f8e4cd4fc4a' 
  AND token = 'syBumWVlm6dwbqx5Z8R/4TIJNPTgfhqs7xjNVFSSwIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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