SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e83a1d7858066f47ede19b8fe74d64abc5cc29294e5204792605a39141ead437' 
  AND token = 'yPMxx/gP0Rc7cayRM97qtPXFNcN0tUD5eThOtIuxdNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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