SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0812b81cfcbce6ad8a15deeeac934877f5b35fab2f472cb82a651cab8c25b3a3' 
  AND token = 'VBNO7vUuC/bR5V4tQZNsL7LHgUPytoB6bPU5lEGMSbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}