SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29ec2aad48485e4293ebbcc4adaaf5901fd0d6b17d83c2901df4fee6cf408b46' 
  AND token = 'UolyWG7fxZYBU7uzqm7O70w8nrFOH/F5fpiH2jJQTPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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