SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9c82bde1b9754dca22043101797f5a32a26eb766608f86b2fa90405374f5d3d' 
  AND token = 'EN+WLKvuz8RC4nP5xqMgUxAt4j6x3XCxX73nwpgm/3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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