SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71a2326da57c6ba2ef4234ee4dddb41156b268a85ef07221c6d13d6c65adfc53' 
  AND token = 'djobEhqQVkPbMzbU1BAgvKjHfoEXrpyZ6RGpGyRnEBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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