SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a87a3d97a4dd5ea2673b5863607b344c5e6d5d3550d2b119f284e95c2df9c09' 
  AND token = 'Co4AIb3BBE0eAAaXFboJQ8ade53XTG4avATa6GuxLGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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