SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '809efbe7c710e3286304c1256da66a35b774fa095b92666edd90f7634a02ce53' 
  AND token = 'cabjpzOVwLMBWnPFfws4yt24O/ymANTEMTjzBJ3wP6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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