SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07bc4114270192d47142dbaaae264a860acdc0cf735810afbf77ae3671196f1c' 
  AND token = 'zymC4Fi/1DCpswEZcGK2cL5Xg7SkA64wcQwOxSnKIPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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