SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0e1ef30df1799364014cf83822d4170536116b85cb8d55fc07e084d8ad1251f2' 
  AND token = 'JPK1LpFTUZdnIoobfxy6VHemz8ZH0gRvnocOfXCookg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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