SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b542b566f99dbcfddbd111253ac878d37936ebac77e59adb88d8c53cd143f6c' 
  AND token = 'NTa7VNCgN9s2OvQ6AHB5QCvKylXvpSj2YGlGUbzAUG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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