SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2ba6415bdd67460161f73eb1e1b2ea2239473c5e4b3ce5497d424edef150898' 
  AND token = '3rzMXTV08ldW9C/+QVq039CnYAztOWaaB0qorcz8sB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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