SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e4a65f8099d41808133521d62f37831017e1412387a7bc2044a1bbec6d113dd' 
  AND token = 'ShWkSnc3yOfXpBq2viW3u86Kv22i160R7/TWPyNom+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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