SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c62d9488745d37a2c0e30573157fcaa716995ca421cd40787da393c69486fbe' 
  AND token = 'hlHXMwu3a0JvHyOshlWvy68Xk/Fr8GrA87nUVG6SHYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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