SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea9b81fd5c0e9efebebcdf50045dab26a640dbf253efbaad2843144ed5fcafb2' 
  AND token = 'YPIoGjEI+tleUU54M/2IfwSs8GZHpZmMUN2/WOwtdTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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