SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f8fd4ce6136c029771381022c2caf23ccefb16ad31018625dc4fdf5eb86970a' 
  AND token = 'BN7ZY/+1NV3UQZic3Y5rK4MHyrVknpyiZGATkHJ6iRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}