SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef5a584fb2bfbfda632b5bdae994ea14f40c898842f8f1a606877922cceed3c5' 
  AND token = '0CK4zyY1Vwpn2QLvCUvlVUiNW+jR4r0zW2YCzWKZjZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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