SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bc44a64e770fb53f4b23bfac30a4d9b4952d4ac13d9d3f56f22da6aa12c8d83' 
  AND token = 'w7ZtBIVJG22rCwYCL0ByqP3BG/3+tOZVnSFB3qQqYQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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