SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e69be5d558a5d06cef39a4ab452265b3125125f3d730b57cd17a0240548d4c19' 
  AND token = 'pN1mB66WEGDLUCuqhKmwHtYMPeupmirVWb5Umfwptpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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